Notwithstanding the important roles of calcium and magnesium ions in plant growth and development, the use of fertilizers containing them is not yet a common agricultural practice inThe green-life of fruits produced by these two tomato varieties that received T 1 was respectively 10 and 6 days longer than that of control fruits. T 2 prolonged the shelf-life of fruits from those varieties by 4 and 12 days respectively. On the whole, Rio Grande and Rio de Grenier plant were the tomato varieties whose health, growth, development, yield and fruit quality parameters were the most positively affected by treatments with fertilizers containing calcium oder magnesium. Roma tomato plants were affected to a lesser extent by these treatments. These results could be interpreted in terms of a temporal shift in the resistance of tomato plants to P. infestans and S. lycopersici on the one hand and A. solani and F. fulva on the other hand and also in terms of similarities of responses of closely related tomato varieties to fertilizers.